In another respect also we have to complain of Hipparchus, because, as he had given a category of the statements of Eratosthenes, he ought to have corrected his mistakes, in the same way that we have done; but whenever he
has any thing particular to remark, he tells us to follow the
ancient charts, which, to say the least, need correction infinitely more than the map of Eratosthenes.

The argument which follows is equally objectionable, being
founded on the consequences of a proposition which, as we
have shown, is inadmissible, namely, that Babylon was not
more than 1000 stadia east of Thapsacus; when it was
quite clear, from Eratosthenes' own words, that Babylon
was above 2400 stadia east of that place; since from Thapsacus to the passage of the Euphrates where it was crossed
by Alexander, the shortest route is 2400 stadia, and the
Tigris and Euphrates, having encompassed Mesopotamia,
flow towards the east, and afterwards take a southerly direction and approach nearer to each other and to Babylon at
the same time: nothing appears absurd in this statement of
Eratosthenes.